1. Field of the Invention
The present invention relates to a serial bus system, and more particularly to a slave device which receives the assignment of a device identification address from a master device on a daisy chain serial bus.
2. Description of the Related Art
For a communication system in which various devices are interconnected by a serial bus, it requires device identification address assigned in each device such that a message can be sent from a source device to a destination device. Ethernet developed by Xerox Corp., is a popular serial bus network system used in local area network. A unique 48-bit address is commonly pre-assigned to each Ethernet interface adapter device. The packet data of Ethernet frame includes a destination address field and a source address field.
LocalTalk developed by Apple Computer Inc., is a serial bus interface for interconnection between computers and computer peripheral devices such as key board, mouse, and printer. LocalTalk uses a dynamic device identification address assignment technique for a device to choose its own device address through a sequentially query procedures to find out a valid address when the device is connected on the bus.
Universal Serial Bus (USB) is a serial bus that supports data exchange between a host computer and a wide range of simultaneously accessible peripherals. This technology is used in U.S. Pat. No. 5,623,610 to Knoll et al., The root hub provides the connection between the Host Controller and one or more USB ports. The USB port is an attachment point for hub device or function device to connect with USB host. When an USB device is attached on an USB port, the device address is assigned by the USB host through a device configuration procedure.
Inter-Integrated Circuit (IIC) serial bus interface defined by Phillips Semiconductors is a 2-wire serial bus with a data wire and a clock wire. IIC is one of the popular serial bus interface scheme used to transfer data between various integrated circuit devices. The operation of data transfer is controlled by a master device and each slave device on the bus should have a unique device address pre-assigned for it.
U.S. Pat. No. 5,710,869 to Godefroy et al. teaches a daisy chain serially connected to the two adjacent neurons which distinguishes between the two possible states of the neuron circuit.
U.S. Pat. No. 6,799,235 B2 to Bormmann et al. teaches a serial daa transmission, a device determines if the serial data word is addressed to a first device having an address and to a second device if the serial data word is not addressed to the first device.
U.S. Pat. No. 7,013,355 B2 to Chambers teaches an incremental or bit by bit address decode scheme allows each device on a serial bus to determine if it is the device being addressed by the master device.
For serial bus device pre-assigned address at manufacture or set by user have no flexibility in installation. For which get device address automatically at connection needs more hardware and software costs and additionally limited only in two way communication architecture systems.